1. Field of the Invention
The present invention relates to transmitters applicable to touch sensitive panels, and more particularly, to transmitters with power saving capacity.
2. Description of the Prior Art
Touch sensitive panels or screens are important human-machine interfaces, especially on consumer electronic products like portable phones, tablet PCs, or Personal Digital Assistances (PDAs). Touch sensitive screens are one of the main input/output (I/O) devices. Since capacitive touch sensitive screens, especially those of projected capacitive types, are very sensitive to finger touches, it has become one of the main design choices for touch sensitive panels/screens on the market. Touching the screen with the tip of a finger will inevitably block part of the screen, such that the user cannot confirm a point that is being detected by the touch sensitive with his/her eyes. In addition, one cannot have as accurate control as using a pen (or stylus) when using their finger tip(s) to write. Therefore, in addition to using the finger tips to touch the screen, the user may also wish to use a stylus for input to the screen.
As the power supply of an active stylus, i.e. one that transmits signals actively, comes from the batteries, in order to reduce the power consumption and increase the life of the batteries, there is a need for a stylus with an automatic power saving feature and a touch sensitive device that accommodates such a stylus.